I'm not sure exactly how to comment, but here goes.
Question 4 of Inventors doesn't have an answer.
I disagree that PTFE (Teflon) is used for a stenting balloon. PTFE does not have the ability to stretch. Instead nylon or PET is used
(source)
The inventor of the stent has several answers I found. Palmaz invented the
balloon-expandable stent (which isn't the same)